Rock Drilling Device and Rock Drilling Rig Incorporating A Pressure Cylinder For Feeding The Drilling Machine

ABSTRACT

The present invention relates to a rock drilling device comprising a feed beam ( 4 ), which has a drill end ( 41 ) from which the drill point protrudes at drilling and a rear end ( 42 ) opposite said drill end. A rock drilling machine ( 5 ) is movable along the feed beam ( 4 ) and a pressure cylinder ( 6 ) is arranged at least partly inside the feed beam ( 4 ) with one end ( 622 ) movable relative to the feed beam ( 4 ) and one end ( 611 ) fixedly arranged relative to the feed beam. A feed line ( 51 ) is driven by the pressure cylinder ( 6 ) and connected to the drilling machine ( 5 ) for feeding it to and for along the feed beam ( 4 ). At least a part of the pressure cylinder ( 6 ) is arranged inside the feed beam ( 4 ) and the fixed end ( 611 ) of the pressure cylinder ( 6 ) is arranged at the rear end ( 42 ) of the feed beam, the pressure cylinder ( 6 ) being adapted to feed, via said feed line ( 51 ), the drilling machine ( 5 ) to and for along the feed beam. The invention also relates to a drill rig comprising said rock drilling device.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a drilling device, in accordance with the preamble of the independent claim. The invention also relates to a drill rig comprising such a drilling device.

BACKGROUND OF THE INVENTION

One of the most important features of a drill rig is its durability and reliability. All parts of the equipment need to answer to the high demands that are required in the extreme working operations of a drill rig. It is also important that its accuracy can be withheld in these condition. Therefore, improvements that ameliorate the endurance, accuracy and reliability of the equipment is always sought for.

Generally (see FIG. 1), a rock drill rig comprises a movable carrier 1, a boom 2 and a feed beam 4 connected to the boom 2 via e.g. a feed beam holder 3. The feed beam 4 and the feed beam holder 3 are movable in relation to each other along at least part of the length of the feed beam, which permits relative movement between them. A drilling machine 5 is movably arranged on the feed beam 4. It is common to use a channel beam as feed beam as it has one open side, where the drilling machine can slide, and which provides an opening through which the drive means, can be connected to the drilling machine for moving the drilling machine to and fro along the feed beam.

As the feed beam is exposed to great mechanical stresses under operation its structural strength is of uttermost importance. There are, however, limitations on the size and weight of the feed beam in order to keep it manoeuvrable. It is therefore desired to use an alternate beam construction that has a higher structural strength than the open channel beam, but which has the same thickness as, or is even thinner than, the channel beam. These characteristics are provided by the box beam. However, the use of a box beam, which is a closed beam, implies that the feeding of the drilling machine needs to be arranged in an alternate way, as there can be no connection along the feed beam between its interior where the drive means preferably is arranged and its exterior where the drilling machine is slidably arranged. Traditionally, when using a box beam, the driving means has been arranged to drive the shaft of a gear wheel, which is connected to the drilling machine via sprocket and chain. Such an arrangement is schematically shown in FIG. 2, where a drilling machine 5′ is slidably arranged via sliding elements 50′ on a feed beam 4′ of the box type. A chain 51′, which is driven by a feed engine 6′ is utilised to move the drilling machine 5′ along the feed beam in the directions of the arrows A, B. The chain runs over two sprockets 52′, 53′ arranged at each end 41′, 42′ of the feed beam 4′, whereby part of the chain 51′ can run inside the beam. The arrangement allows for the use of a box beam instead of a channel beam as no connection between the interior of feed beam and the drilling machine is needed along the feed beam.

However, it has proven advantageous to use a pressure cylinder for moving the drilling machine along the feed beam as it provides a more reliable and steady feeding.

U.S. Pat. No. 6,550,544 B1 discloses a rock drilling device, in which a pressure cylinder is used to provide a means for moving the drilling machine along the feed beam. In this arrangement a feed line is routed over a sheave that is arranged at a movable end of the pressure cylinder. This arrangement is, as has been described above, impossible to use in a box beam.

BRIEF DESCRIPTION OF THE INVENTION

The main object of the present invention is to achieve an arrangement that overcomes the drawbacks presented above and that makes it possible to use a pressure cylinder to move a drilling machine along a closed feed beam. Another object of the invention is improve the efficiency of the pressure cylinder such that its exerted power is utilised to a maximum. This is solved by the features set forth in the characterising portion of the independent claim.

Preferred embodiments of the invention are set forth in the dependent claims.

According to a main aspect, the present invention relates to a rock drilling device comprising a feed beam, which has a drill end from which the drill point protrudes at drilling and a rear end opposite said drill end; a rock drilling machine movable along the feed beam; a pressure cylinder, which at least partly is arranged inside the feed beam with one end movable relative to the feed beam and one end fixedly arranged relative to the feed beam. A feed line is driven by the pressure cylinder and connected to the drilling machine for feeding it to and fro along the feed beam. The fixed end of the pressure cylinder is arranged at the rear end of the feed beam and the feed line is routed over two outer sheaves that are fixedly arranged at each end of the feed beam.

This arrangement makes it possible to use a pressure cylinder inside a box beam, whereby the advantages of the box beam and the advantages of the pressure cylinder is combined in one embodiment. Furthermore, with the pressure cylinder fixedly arranged to the rear end of the feed beam, and not to the drill end, the power of it is utilised much more efficiently. The pressure cylinder namely exerts more power when it expands than when it contracts and this additional power is needed when the drill is being pulled out of the ground rather than when the drill is being pushed into the ground.

These and other aspects and advantages of the present invention will be apparent from the detailed description and the accompanying drawings.

SHORT DESCRIPTION OF THE DRAWINGS

In the detailed description of the present invention reference is made to the accompanying drawings, wherein:

FIG. 1 is a schematic view of a rock drill rig;

FIG. 2 is a schematic view of a feed beam with a prior art driving mechanism;

FIG. 3 is a schematic view of a feed beam with a drilling machine driven by pressure cylinder in accordance with the invention;

FIG. 4 is a cross sectional view taken along line 4-4 in FIG. 3 showing a feed beam with a drilling machine in accordance with the invention.

FIG. 5 is a cross sectional view taken along line 5-5 in FIG. 3 showing a feed beam with a drilling machine in accordance with the invention.

DETAILED DESCRIPTION

As briefly discussed above FIG. 1 shows a schematic view of a rock drill rig comprising a movable carrier 1, a boom 2 and a feed beam 4 connected to the boom 2 via a feed beam holder 3. The feed beam 4 and the feed beam holder 3 are movable in relation to each other along at least part of the length of the feed beam 4. A drilling machine 5 is movably attached to the feed beam 4, and is movable along the feed beam 4 to affect the drill string 10. The drill string 10 comprises the drill point (drill bit) and joined rods (not shown). Other equipment attached to the feed beam 4, may be equipment for e.g. rod handling.

Now with reference to FIG. 3, the feed beam 4 has a drill end 41 from which the drill point protrudes at drilling, and a rear end 42 opposite the drill end 41. A pressure cylinder 6 is arranged inside the feed beam 4. The pressure cylinder 6 is adapted to drive the drilling machine 5 to and fro along the feed beam using a feed line 51. The feed line may be a chain or a wire or any other line that is sufficiently strong and unyielding. In the preferred embodiment of this invention a wire is used as feed line. In practise it may be advantageous to use two feed lines, one at each side of the drilling machine, which are fixed to opposite sides of the drilling machine. However, the number of feed lines does not affect the general arrangement involved in the invention except for the fastening arrangements for fastening the feed line or feed lines to the drilling machine. Suitable fastening arrangements are well known in the art and therefore this is only briefly covered by this application.

Means 52, 53, 54, 55 for low-friction passing of the feed line 51 are arranged at both ends of the feed beam as well as inside it. Preferably these means consist of wheels or sheaves 52, 53, 54, 55 with an internal bearing that provides low friction against the respective shaft. The term sheave that is used in this application should be understood in a broad sense that does not exclude any other type of known means that are suitable for allowing a low-friction passing of a feed line.

The pressure cylinder 6 may be of any conventional type involving two cylinders, one outer cylinder 61 and one inner cylinder 62 that slides hydraulically within the outer. The outer cylinder 61 has one outer end 611, which preferably is fixedly arranged to the rear end 42 of the feed beam and one inner end 612, from which the inner cylinder 62 extends. Naturally, and within the scope of the present invention as it is defined, by the appended claims, the invention is not limited to the use of only one pressure cylinder 6, but any suitable combination of two or more pressure cylinders arranged to achieve the required movement may be used. The pressure cylinders may be arranged at the same end or at opposed ends of the feed beam. However, when one pressure cylinder is arranged at the rear end, as in the preferred embodiment in FIG. 3, the additional power it exerts when it expands can be utilised to pull the drill out of the ground. When the drill is pushed into the ground the main work is done by the drilling performed by the drilling machine and the power that can be supplied by the contracting pressure cylinder is therefore well enough. Yet another alternative is to fix the inner cylinder to the feed beam and let the outer cylinder be free to move. It is, however, advantageous from a mechanical point of view to attach the heavier outer cylinder and let the inner cylinder move to and fro. The inner cylinder 62 has one end inside the outer cylinder at all times. The other end 622 of the inner cylinder is provided with a holder 625 that houses two sheaves 54, 55 over which the feed line 51 passes. The ends of the feed line 51 are fixed in fixing devices 511 and 512 of a conventional type, which also includes stretching devices (not shown) to avoid any slacking of the line. A first fixing device 511 is arranged to the inner end 612 of the outer cylinder 61. The feed line passes from this first fixing device 511 over the closest sheave 55 of the two sheaves arranged on the holder 625 on the inner cylinder to and over the sheave 52 at the drill end, where it exits the feed beam and eventually reaches the drilling machine 5. The feed line 51 continues on the other side of the drilling machine and passes over the sheave 53 at the rear end 42 of the feed beam where it enters the feed beam 4, it then passes over the foremost sheave 54 of the two sheaves on the holder 625 on the inner cylinder, and is routed back towards the drill end 41 of the feed beam where its second end is fixedly arranged to the second fixing device 512. Hence, the feed line is for most parts running inside the feed beam. Generally, the only part of it that runs outside the feed beam is the part where it is attached to the drilling machine 5, between the two sheaves 52, 53 at the respective ends 42, 41 of the feed beam.

With reference to FIG. 4 and FIG. 5, which are cross sectional views taken along lines 4-4 and 5-5 in FIG. 3, respectively, the drilling machine is arranged with bolts 56 to a sled 43. An insert or spacer 59 is arranged between the drilling machine 5 and the sled 43. The sled holds the sliding elements 50 via bolts 58. Each sliding element comprises two low friction abrasion resistant contact elements 45, which slides directly on the feed beam 4. The feed line is attached to the sled 43 at fastening arrangements 57 placed under the sled 43. When two feed lines are used, one at each side of the drilling machine, the ends of these are preferably fastened to two separate fastening arrangements 57 at each side of the sled 43. If only one feed line is used only one fastening arrangement is needed. In order to keep the feeding accurate it is however important that the fastening arrangement is sufficiently tight such that the sled and hence the drilling machine responds directly, in both directions, to any movement implied to it via the feed line by the pressure cylinder.

The pressure cylinder has an outer housing 63, which fits tightly inside the feed beam. The inside of the feed beam 4 is provided with recesses 46 in which projections 66 of the housing fits. The outer cylinder 61 is attached inside the housing 63, while the smaller inner cylinder 62 is arranged to slide inside the outer cylinder 61 under the influence of a hydraulic fluid.

FIG. 4 shows how the holder 625 is slidably arranged inside the feed beam. The holder holds two sheaves 54, 55 over which the feed line shall run. The sheaves are arranged on shafts 627 via bearings 541. The holder 625 is provided with protrusions 626 at both sides, which are arranged to slide within the recesses 46 of the feed beam. The protrusions 626 guide the movable end 622 of the inner cylinder 62 inside the feed beam (4). In order not to wear down the cylinder they are preferably provided with a low friction coating and preferably they are exchangeable and softer than the beam material so that the protrusions will get wore down rather than the beam.

The present arrangement with two outer sheaves 52, 53 at respective ends of the feed beam makes it possible to use a box beam as feed beam, additionally the sheaves 52, 53 constitute ideal locations for placing a measuring device for measuring the exact location of the drilling machine along the feed beam. A measuring device can be placed at either or both of the outer sheaves. However, in the preferred embodiment, as depicted in FIG. 3, the measuring device is placed on the extension of the shaft 9 of the rear sheave 52. the placement of the measuring device is indicated by arrow 7. In order to make the arrangement work, the sheave 52 must be fixedly arranged to the shaft 9 such that the shaft and the sheave 52 rotate together. It is then possible to monitor the movement of the feed line 51 and hence the drilling machine 5 by measuring the rotation of the shaft.

The described arrangement where the pressure cylinder is arranged at the rear end of the feed beam is naturally equally applicable on a box feed beam as on a channel feed beam. 

1. Rock drilling device comprising a feed beam (4), which has a drill end (41) from which the drill point protrudes at drilling and a rear end (42) opposite said drill end; a rock drilling machine (5) movable along the feed beam (4); a pressure cylinder (6), which at least partly is arranged inside the feed beam (4) with one end (622) movable relative to the feed beam (4) and one end (611) fixedly arranged relative to the feed beam (4); a feed line (51), which is driven by the pressure cylinder (6) and connected to the drilling machine (5) for feeding it to and fro along the feed beam (4), characterised in that the fixed end (611) of the pressure cylinder (6) is arranged at the rear end (42) of the feed beam (4) and that the feed line (51) is routed over two outer sheaves (52, 53) that are fixedly arranged at each end (42, 41) of the feed beam, the pressure cylinder (6) being adapted to feed, via said feed line (51), the drilling machine (5) to and fro along the feed beam (4).
 2. Rock drilling device according to claim 1, characterised in that two inner sheaves (54, 55) are arranged on the movable end (622) of the pressure cylinder (6) inside the feed beam (4), the feed line (51) being arranged such that it passes from the outer sheaves (52, 53) over the inner sheaves (54, 55) to its two endpoints where it is fixedly arranged (512, 511).
 3. Rock drilling device according to claim 1, characterised in that the pressure cylinder (6) comprises two cylinders (61, 62), one outer cylinder (61) and one inner cylinder (62) that runs inside the outer cylinder (61), wherein the outer cylinder is fixedly arranged at the rear (42) end of the feed beam (4).
 4. Rock drilling device according to claim 1, characterised in that the feed beam is a box beam.
 5. Rock drilling device according to claim 1, characterised in that a measuring device that measures the location of the drilling machine (5) relative to the feed beam is arranged at one or both of the outer sheaves (52, 53).
 6. Rock drilling device according to claim 5, characterised in that the measuring device is arranged to the shaft (9) of a outer sheave (52, 53) and that the sheave (52, 53) and shaft (9) are integrated such that they rotate together.
 7. Rock drilling device according to claim 6, characterised in that the measuring device is arranged on the shaft extension.
 8. Drill rig comprising a rock drilling device according to claim
 1. 9. Rock drilling device according to claim 2, characterised in that the pressure cylinder (6) comprises two cylinders (61, 62), one outer cylinder (61) and one inner cylinder (62) that runs inside the outer cylinder (61), wherein the outer cylinder is fixedly arranged at the rear (42) end of the feed beam (4).
 10. Rock drilling device according to claim 2, characterised in that the feed beam is a box beam.
 11. Rock drilling device according to claim 3, characterised in that the feed beam is a box beam.
 12. Rock drilling device according to claim 2, characterised in that a measuring device that measures the location of the drilling machine, (5) relative to the feed beam is arranged at one or both of the outer sheaves (52, 53).,
 13. Rock drilling device according to claim 3, characterised in that a measuring device that measures the location of the drilling machine (5) relative to the feed beam is arranged at one or both of the outer sheaves (52, 53).
 14. Rock drilling device according to claim 4, characterised in that a measuring device that measures the location of the drilling machine (5) relative to the feed beam is arranged at one or both of the outer sheaves (52, 53).
 15. Rock drilling device according to claim 10, characterised in that a measuring device that measures the location of the drilling machine (5) relative to the feed beam is arranged at one or both of the outer sheaves (52, 53).
 16. Rock drilling device according to claim 11, characterised in that a measuring device that measures the location of the drilling machine (5) relative to the feed beam is arranged at one or both of the outer sheaves (52, 53).
 17. Drill rig comprising a rock drilling device according to claim
 2. 18. Drill rig comprising a rock drilling device according to claim
 3. 19. Drill rig comprising a rock drilling device according to claim
 4. 20. Drill rig comprising a rock drilling device according to claim
 5. 